Elixir doctests

gistfile1.ex

defmodule AndrewEnum do

  @moduledoc """
  A reimplementation of the standard `Enum` module.
  """

  @doc """
  Invokes the given `fun` for each item in the `collection`.
  Returns `:ok`.

  ## Examples

      iex> AndrewEnum.each([], fn -> end)
      :ok

      iex> AndrewEnum.each([1, 2, 3], fn(x) -> Process.put(:andrew_enum_test_each, x * 2) end)
      iex> Process.get(:andrew_enum_test_each)
      6

  Note that the above example as a doctest is a bit contrived, but I
  need *some* kind of side effect to assert on for AndrewEnum.each. I
  stole the idea of stuffing state into the process dictionary via the
  `Process` module from `elixir/enum_test.exs`.

  Another note, but this doesn't *completely* replicate Enum.each since
  it only accepts a list and not *any* `Enumerable` collection.
  """
  def each([], _), do: :ok
  def each([head|tail], fun) do
    fun.(head)
    each(tail, fun)
  end

end

defmodule AndrewEnum.Test do
  use ExUnit.Case
  doctest AndrewEnum
end

# ❯ mix test
# ..
#
# Finished in 0.06 seconds (0.06s on load, 0.00s on tests)
# 2 tests, 0 failures